chapter 1-3 (intro to bio, chemistry of life, water and life)

What are the basic characteristics or hallmarks of life?

All living things are composed of cells, process energy, grow and develop, adapt through natural selection, regulate internally or maintain homeostasis, reproduce, respond to the environment, move, communicate, and possess DNA for ATP and anti-entropic processes

What is the difference between order, energy processing, growth, and development?

Order refers to organized structure, energy processing refers to using energy to power life, growth refers to increase in size, and development refers to life cycle changes

What are the levels of biological organization?

Atoms, elements, molecules, organelles, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystems, biosphere

What is the difference between eukaryotic and prokaryotic cells?

Eukaryotes have nuclei and organelles, prokaryotes do not

What are reductionism and emergent properties?

Reductionism breaks systems into parts, emergent properties arise from interactions of those parts

What is the genetic library of a cell?

The full DNA content including genes and chromosomes

What is feedback regulation?

Negative and positive feedback mechanisms that maintain stability, like temperature or oxytocin release

What are the three domains of life?

Bacteria, Archaea, Eukarya

What accounts for life’s diversity?

Darwin’s descent with modification through natural selection

What is science?

The scientific method: observation, questioning, hypothesis, experimentation, analysis, and conclusion

What are pseudoscience and junk science?

Claims that appear scientific but lack proper testing or credible evidence

What is the difference between basic and applied research?

Basic research expands knowledge, applied research solves practical problems

What elements make up most of the human body?

Hydrogen, carbon, oxygen, nitrogen

What other major elements are important?

Calcium, phosphorus, potassium, sulfur, sodium, chlorine, magnesium

What are trace elements?

Elements needed in small amounts like iron, zinc, silicon

What are atoms made of?

Protons, neutrons, electrons

What are atomic number and mass?

Atomic number is protons, mass is protons plus neutrons

What are isotopes?

Same element, different neutrons

What is energy in biology?

The capacity to do work

What determines atom bonding behavior?

Valence electrons and the octet rule

What are covalent bonds?

Electron-sharing bonds, can be polar or nonpolar

Why is water polar?

Oxygen has higher electronegativity, creating partial charges

What is a hydrogen bond?

Weak attraction between partially charged atoms

What are ionic bonds?

Electrons transferred, forming charged ions

What are Van der Waals interactions?

Weak attractions from temporary charge shifts

What is oxidation vs reduction?

Oxidation is electron loss; reduction is electron gain

What causes cohesion and adhesion?

Hydrogen bonds create cohesion; attraction to other surfaces creates adhesion

What is water’s specific heat?

High (1 calorie), helps stabilize temperature

What is heat of vaporization?

High (580 calories), helps with evaporative cooling

Why is ice less dense than water?

Hydrogen bonds spread molecules apart when frozen

Why is water the solvent of life?

Polarity dissolves many substances

What are hydrophobic vs hydrophilic substances?

Hydrophilic mixes with water; hydrophobic repels water

What is the pH scale?

Measures H+ concentration from 0–14

What happens when acids or bases are added?

Acids increase H+, bases increase OH– or remove H+

What are buffers?

Substances that resist pH changes, like the carbonic acid–bicarbonate buffer

What is acid rain?

Any precipitation with pH below 5.2

What is ocean acidification?

Excess CO₂ lowers ocean pH and reduces carbonate needed by marine organisms